Right now we’re receiving a fair bit of email relating to the cloudy haze and appearance of porcelain tiles, especially those sourced from countries like China. Here’s one of the latest:
Question: “We have had porcelain tiles laid and there is a very distinctive cloudy appearance all over the tiles. We have tried many tile shops and tried their residue removers but with no luck. We have had a tile company come and look at our tiles and tried their solution but still no luck. We’re beginning to wonder if the tiles are faulty as we purchased them from a Chinese warehouse. Please can you help as very disappointed with them?”
Our Answer: “Hi, sorry to say that this sounds like yet another example of what is
becoming a classic problem with imported modern porcelain from certain sources. The distinctive cloudy appearance you report, is most like a grout haze.
This type of porcelain tile can have many microscopic holes (like tiny gas
bubbles – think of the holes in a loaf of bread) in the body. The polishing process removes a fine layer of the tile’s surface, just as using sand paper on wood does. This process can take the tops off some of those holes, thus exposing them, we cannot see them too easily as they are so small.
However, the grout is smeared all over the surface and some of the liquid containing cement, water, polymers and pigments) can be forced into these holes any sand in the grout would be too big). When the tiles are washed to remove the surplus grout, it can be very difficult to remove the coloured ‘grout water’ from those tiny holes.
So, it remains there and is allowed to dry. There are so many of them that when you look at the tile they all appear to merge into one – like pixels in a TV image giving an all-over cloudy or hazy appearance.
These tiles would have benefited from sealing prior to grouting but there are a number of things you can try. Given that you have tried several cleaners already, I am going to assume you have tried a proprietary grout haze remover (acid based) so I would try one other thing, before moving on to a last-chance, combination approach.
First I would try MicroscrubTM, this is a micro-abrasive cream cleaner. The abrasive is derived from calcite and is soft enough so as not to damage the tiles, but it might just provide enough gentle abrasion to remove some of the grout. It also contains nanotechnology which simply means it can get into some of the micro pores – so worth a try.
If that fails, go for the combined approach:
First apply a solvent based stripper, neat spread over the affected area and leave for 30 to 40 minutes, Then, without removing the solvent, now add to the floor, some diluted grout haze/cement cleaner, (make sure it is based on phosphoric acid or similar and not HCL), leave the two chemicals for another few minutes (the first product is attempting to break down any polymers present, this takes time, once it has done this there is more chance that an acid can now work on any cement present).
At this point, add some MicroscrubTM – just a couple of blobs, mix it into the solution and leave again for a few more minutes (the nano particles in the product help to allow the chemicals to ‘go deeper’). Don’t worry about the acid wanting to react with the calcium in the MicroscrubTM, by now the acid cleaner will be mostly spent, and it’s job done (this is why we wait until the end to add the MicroscrubTM). Now scrub, with a white nylon pad and really try to work the mixture into the tile. Clean up the slurry and rinse well with clean water.
I hope this improves the situation, more often than not it does, but there are some situations that cannot be saved; sometimes it is not so much the grout haze, but a waxy coating (a very stubborn one) that gives this appearance (the above procedure may well help with that anyway). Other times there can be a polishing fault in the tile, in that the tile has not been correctly finished at the factory – this cannot easily be rectified.
I hope this has been helpful. If you have no joy, perhaps you could send us a picture?
Copyright Ian Taylor and The Tile and Stone Blog.co.uk, 2013. See copyright notice above.
Hi Karen,
Great questions,
You have basically got the process correct, I can just add a few things
First of all the fact that they recommend a grout release – suggests they are concerned about staining from grout pigment – when they actually say this it is a pretty sure bet the tiles have a micropores in the surface – so yes, lay the tiles then seal before grouting.
However just check that you don’t first have to remove a transit wax (as if so and you don’t, the sealer wont get in but the grout can stain through the wax – I have seen this happen.
The other thing is , there are temporary sealers, even more temporary grout release products (basically just soapy products that wash straight off) and there are good sealers.
It may be that you need a sealer ongoing (if you are going to seal the grout, you may as well seal the tiles also, they will take in whatever sealer they need)
so, it might be better to not go for a temporary sealer, but to go with the ultimate sealer that you intend to use on the grout – this way it wont need removing after, and when yo come to seal the grout, you will be topping up the seal to the tile wherever needed.
so in this case you might have the following procedure: lay tiles, remove transit wax, seal, grout, seal again
making sure to rinse after cleaning of course and to allow adequate drying times for each stage.
You appear to be in Canada, I have a contact there who could advise you on products if you like, if so please use the contact form on the blog to email me personally and I will reply
Hope this helps
ian
Thank you for your help. I would love a contact person, and i’ve emailed you at the contact form.
I’m going to try to take the wax off on a sample now and also try the sealer to see the effect.
So for wax removal, I should try the following, from least aggressive to most aggressive:
-warm/hot water and scrub pad
-concentrated Tile and Stone Cleaner
-Alkaline degreaser +warm water + scrub pad
-Solvent stripper + scrub pad
-Abrasive cleaner + nanoscrub
Then for impregnator Sealer:
Utra Solv
– To save myself some work, I was considering phoning the distributor of the tile in Canada, which is on the Dal Tile website, on the pdf of the tile, and i was going to ask them whether there is a wax on the tile. Do you think their answer will be reliable – i ask because i’ve noticed that no one seems to really know much about much in the porcelain world, probably because it’s just the state of the world at the moment.
– Finally, I don’t know whether you can help on this question, but I’m wondering whether black tile is a mistake in that it will show all the dirt versus gray tile which might not show as much. I prefer the black, but don’t want a cleaning headache.
So appreciate your blog and all your knowledge,
Karen
Addendum, sorry for this,
Can I remove the wax before they putting the tiles down?
And, just to be clear, when putting on the impregnator, I should use a paint pad and apply a thin coat, and let it sit for 5 minutes, and wipe it off before getting dry.
So when redoing this step after grouting, I should make sure to do the same so as not to get the problems some people are talking about.
thanks again in advance,
karen
Hi Karen
OK, Well you really have been reading my blog!
yes, your procedure is ok, you may find that the neutral cleaner does little to remove wax (if there is any) but you could try the abrasive cleaner (nanonscrub or similar) then the alkaline etc.
You can ask the distributor and to be honest they ‘should’ know the answer, but whether they will I cannot say – doing your own test should help though.
You are spot on, on the sealer application and yes, well spotted, you do it exactly the same way the second time even though you are really focused on the grout.
is black a mistake? – how can I answer this without drawing the wrath of multiple tile manufacturers and distributors??
what I can say is – I would probably not buy one, at the moment, for myself, at least not before I conducted some stain tests (with contaminants that the tile is likely come into contact with).
But it is not just a staining issue, there are certainly some hi quality black polished tiles out there that are fine – but even they can have an issue for two reasons:
1) if you have black (particularly but not exclusively shiny/polished ) tiles and the nature of your local ‘dirt’ is that it is light coloured (if your mud is clay based for example) then it will show up like crazy – this is no fault of the tile – just the way it is.
2) Secondly, and perhaps more importantly is this: porcelain tiles, if polished, are so dense, that material sits on the top. Even if there is a staining potential – we are talking about probably less than 1% of whatever liquid contaminant is applied, actually getting into the tile – so more than 99% sits on the top.
Porcelain is the closest form of ceramic material in the tile world to glass, without actually being glass. If we were to wash a window, most of us would know without being told, that if we just wash and rinse, and then leave it to dry, we will get streaks and water marks – just from plain water! – why, because there is no such thing as pure water in practical terms (I don’t know many people who buy their washing water from industrial laboratories) so, what comes out of the tap, is carrying impurities – for example, calcium, in varying amounts around the world, amongst other things. If we do not wipe the water away, then when the water evaporates, whatever is in suspension in the water, is left behind – so we get calcium deposits or other mineral deposits – and this is seen as a fine water mark or streak on the glass. Well exactly the same is true for our glass-like porcelain – so it is prone to streaking and water marks and the like, even if it is a hi quality tile that does not stain.
the only way to avoid this is to buff the floor dry after mopping
Hope this helps
Ian
Dear Ian, thanks for the advise. Yes I have taken some pics of the more prominent stains and is watching if it does improve over time. Please share with me if someone do found a solution to solve this problem.
Thanks a lot, have a nice day!
Hi Ian,
We had our bathroom tiled in Black Porcelain Tiles about a year ago. In the shower area we have noticed white/grey haze on the tiles. It looks like its a little way into the tiles though, we treated the tiles once they were laid and our cleaner uses Limelite at least twice a week on them. We have treated them again since they have started looking aged, but wonder if you could recommend something.
Thanks, Zoe
Hi Zoe,
OK, sounds like hard water deposits to me – the water from the shower leaving behind a very thin film of calcium from the water , it is invisible to begin with but much like stalagmites and stalactites in a cave, over time it builds up to form a white/grey coating.
The limelite, which I assume to be mildy acid based may well help actually, but it could be that it is not strong enough – suggest you try a cleaner based on Phosphoric acid such as HG Extra – there are others also.
It should not have gone ‘into the tiles’ but be on the surface,. If the tiles have a microporous surface texture, then they may have taken in a little of the deposit, but it will not be deep, and again cleaning with the right cleaner may well remove it. It might take a couple of goes.
I future, try toweling the shower walls down once every so often, to remove water, (and with it anything in the water) before it gets a chance to dry on the walls).
IT might also be that the acidic limelite cleaner is too strong, and it could be pulling more fine cement out of the grout joints and leaving that on the tiles – I suspect not, but might be worth looking at.
Hope this helps
Ian
Hi Ian
You seem the authority on polished porcelain, we currently have a nightmare scenario and would appreciate your help. We purchased Superblack Polished Porcelain tiles from a well known national tile supplier Al Murad. These are sold as extremely hardwearing and AM even boast on their website how their kitchen floor tiles, and this is one, are very durable and will come up like new with a quick mop. We had a v expensive new kitchen fitted, so finish is paramount, and the tiler layed these. They are laid well, but when we cleaned them up, virtually every tile was scratched and scuffed.
We contacted the kitchen installation company and they took a tile away. They say the tiles appear poor quality and scratch very easily. The tiler has not seen porcelain scratch like this before he says.
I did do my own scratch tests. I took the handle of a metal spoon (not sharp) and applying very little pressure, ran it across the tile and it scratched it. I was not even pressing hard at all. My wife walked over a tile in her high heels and it scratched it also.
I see black polished porcelain in commercial establishments etc, and surely it shouldn’t scratch like this? Looks like the whole lot is going to have to come up.
Hi Gareth
The first thing I would say, and it is probably not the issue but worth ruling out, is this: is the actual tile scratching, or is there some surface coating like a transit wax, or nano sealer that is scratching – this is not uncommon – many porcelain tiles now come from all over the world, standards and practices are massively variable, some come with wax or other coatings that can be quite ‘plasticky’ looking and appear to be a permanent feature but are really intended to be removed. If there was such a coating it is at least possible that this could be removed to reveal a harder material underneath.
However I am thinking this is not the case.
Scratch resistance is one of many properties or characteristics that all ceramic tiles, (and that includes porcelain) are usually tested for, the better factories are happy to publish independently verified test results as they are often keen to show by how much they beat the required standard.
The point is there are some internationally agreed standards for this and many other properties. It would be interesting to see if your supplier can supply you with the published test results for your tile.
For example, (I am a little out of the loop these days but some quick research found this) ISO 1045-6 2010 is as far as I can see the latest internationally recognized standard for ‘deep surface abrasion’ and it is measured in mm3 – (I assume that is the size of the scratch after a given test procedure). The required standard for porcelain seems to be less than or equal to 175 mm3 and many porcelain factories are happy to boast that they achieve less than 150 mm3
Another perhaps easier way to understand is an older test that some still refer to: EN 101 – this uses the MOH’s scale of hardness as a reference. The Moh’s scale uses natural minerals on a scale of 1 to 10. with 1, being the softest, represented by the Talc, a very soft stone, and 10 by Diamond, the hardest naturally occurring substance we know. Each point is 10 times harder or softer than the next one – so something with a Moh’s hardness of 3 (Calcite) is 10 times harder than 2 (Gypsum) etc.
the full scale is:
1 – Talc
2 – Gypsum
3 – Calcite
4 – Fluorite
5 – Apatite
6 – Orthoclase
7 – Quartz
8 – Topaz
9 – Corundum
10 – Diamond
Some common materials – for reference would be:
a. fingernail (2.5 on the Mohs scale)
b. copper penny (3)
c. glass plate or steel knife (5.5)
d. steel file (6.5)
Geologists use these scales to help them classify and identify minerals, for example, if they attempt to scratch a mineral with a steel blade and it scratches easily then the mineral has a lower hardness than 5.5, but if a copper coin does not scratch then it must be >3
OK, porcelain tiles are as close in nature to glass, as say Humans are to Chimps and Bonobos – (well I may not be 100% correct there but to illustrate the point – porcelain and glass are technically very similar, porcelain is a kind of impure glass, both are types of ceramic material derived from varying amounts of fired silica).
Glass plate typically has a Mohs hardness of 5.5 – about the same as a steel knife, Porcelain tiles though are typically a bit harder, often reaching 7 or even 8 on the Moh’s scale.
It is obvious that all materials can scratch, if they are subjected to wear by a harder material, but they can also scratch if they are subjected to wear by a material of equal hardness. So, take a steel file (7) and run it over a talc stone (1) – result will be a deep scratch, a gouge even, but rub 2 diamonds together and they will both scratch. Or, run a steel knife blade over glass plate – both 5.5 – they will scratch.
What happens if you run a softer abrasive over a harder material? – So a steel blade (5.5) over some granite, or a good porcelain – (say 7) then (if we ignore the possible effects of impact and point loading of the pointed blade and the brittleness of porcelain) we would not expect the porcelain to scratch – but we often see a mark, in fact this is a deposit of metal from the blade being left on the tile – (so the porcelain has scratched the steel – which make sense) and these deposits can be a bit of an issue to remove as they can sometimes appear to fuse to the tile
OK, from your description, it seems that the tile appears to scratch somewhat more easily than I might expect a typical porcelain tile to do.
It is true that polished tiles will scratch easier than unpolished and you can see that a hard steel blade (and high heels etc) could be very close in hardness to the tile though.
This link is for a reputable, well known Italian porcelain tile company – you can see that under Surface Mechanical Characteristics, they achieve less than 150 mm3 on the deep abrasion and 7 – 8 on the moh’s scale http://www.atlasconcorde.it/filealbum/18940_0.pdf
SO, what can you do?
1. First rule out any coating
2. Also rule out that the marks you are seeing are not in fact deposits of the metal being left on the tile (what happens when you run a copper coin on the tiles?)
3. Then I would request the test information for your tiles (both Moh’s hardness and Deep Abrasion) as a starting point – see what they are claimed to be. If they are honestly stated, and are low, then at least you know what you have purchased, if they are claimed to be high then you could go to an independent test house and have them tested. There would be a cost to such a test of course. The best known and most experienced test house in the UK is Ceram (now called Lucideon) based in Stoke on Trent – http://www.ceram.com/
You could ask them for a price to carry out the test
All this will do though is allow you to see if the tiles a) meet the advertised or claimed standard, and B) if they meet the recommended ISO and EN standards.
I hope that was of some help
Good luck
Ian
Hi Ian
We had to have the Al Murad tiles pulled up. Not only were they scratching, but rubbing a wet cloth over them (not any cleaning product on, just water) led to blue coming off onto the cloth. Both my file installer and kitchen fitter have said they are totally defective and frankly they looked a right state.
Since then my tile installer has heard of 2 others with the same problem with these tiles.
Given I had Marmox under the tiles, that had to be chipped up, the kitchen looked like a nuclear fallout zone as they did it.
The whole thing has cost me a couple of thousand and lots of hassle.
Legal action comes next.
Regards
Sorry to hear this Gareth – I too have had recent experience of a similar tile, where there was a blue substance coming off under cleaning (although it took a little more than just a wipe with water). But it also left the surface of the tile less shiny.
There are a few issues like this around at the moment.
Ian
Hi Ian
Came across your blog whilst browsing researching my tile problem.
So I’ve just had glazed porcelain tiles put down in my bathrooms (Chinese).
When the boxes were delivered they looked like they had been out in the weather and had water stains on the cardboard.
My tiler laid and grouted the tiles and did not say anything about any abnormalities.
A few days later I noticed a grid pattern on the tops of some of the tiles and had a closer look no notice quite a few had the marks. You cant see the marks by lookig directly down onto them but on particular angles and lighting. Thought maybe they needed a good clean – might just be dirt. First gave a quick mop over with domestic floor cleaner. Didnt make a difference.
Looked up on the internet how to clean porcelain tiles – the vinegar, water and baking powder. Didnt work?????
Then went to the tile shop and showed them some pics and they gave me a product ‘Lift off’ to try. Didnt work.
Went back to the shop and they suggested another couple of products. Didnt work.
When I blow up the pics on my phone it actually looks like it’s the glaze that is damaged and not something stuck to the tiles that needs removal.
Am I right to think that it’s either Kiln Release or Damage to the tiles from being in water for too long? The Grid pattern on the bottom of the tiles has damaged the tops of the tiles that are underneath.
What’s your thoughts please.
Thanks
Michelle
Hi Michelle,
Sorry to hear of your tile woes. I don’t think being left out in water has anything to do with this. This is a manufacturing issue. It definitely sounds like the back grid pattern has been imprinted on the (or perhaps more accurately, into) the face/glaze of the tiles stacked beneath it. It can be the engobe kiln-relase that gets onto the face of the lower tiles in the box but that can sometimes be removed; it depends if it has just been left on the surface or become embedded into it. However it is usally a visible, white pattern. I am not 100% certain of the process but with speed of production being all important these days (time is money) modern factory techniques can produce a porcelain tile – from clay dust, to boxed tiles, in a matter of an hour or so (not long ago making tiles took literally weeks). The tiles are hot off the kiln as they are packed, it can sometimes be possible to pack them too soon, while still in the coooling phase and this is sometimes when we see a transfer of the grid pattern imprinted in adjacent tiles (the glaze is still cooling and not 100% hard?). As I said I am not an expert in the production process but we have seen this kind of issue resulting from cutting a few conrers in order to get production up etc.
Without seeing them, given all you have told me I suspect this is a batch of tiles that are fautly, with a permanant imprinted pattern in them from the manufacturing process. I would press for a representitive of the shop to visit your site and look at them, with a factory rep of possible – I do not see these being rectified other than by replacement. Sorry if that is not what yo want to hear but I don’t think any cleaner is goig to help
Good luck
Ian